Double-J's World

import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Checkbox;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.GridLayout;
import java.awt.Label;
import java.awt.Panel;
import java.awt.Toolkit;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

class CheckboxEx_Sub extends Frame{
   
    private BorderLayout bl = new BorderLayout();
    private GridLayout gl = new GridLayout(2,2);
    private FlowLayout fl = new FlowLayout(FlowLayout.RIGHT);
   
    private Panel panel_center = new Panel();
    private Panel panel_south = new Panel();
   
    private Label lb_description = new Label("번호를 선택하세요.");
    private Checkbox cb1 = new Checkbox("1번");
    private Checkbox cb2 = new Checkbox("2번", false);
    private Checkbox cb3 = new Checkbox("3번", true);
    private Checkbox cb4 = new Checkbox("4번");
   
    private Button bt_ok = new Button("확 인");
    private Button bt_cancle = new Button("취 소");
   
    public CheckboxEx_Sub() {
        super("CheckboxEx");
       
        init();
       
        this.setSize(300, 200);
       
        Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
        Dimension frame = this.getSize();
       
        int xpos = (int)(screen.getWidth()/2 - frame.getWidth()/2);
        int ypos = (int)(screen.getHeight()/2 - frame.getHeight()/2);
       
        this.setLocation(xpos, ypos);
        this.setVisible(true);
       
        //window closing..
        addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e){
                dispose();
                System.exit(0);
            }
        });
    }
   
    public void init() {
       
        panel_center.setLayout(gl);
        panel_center.add(cb1);
        panel_center.add(cb2);
        panel_center.add(cb3);
        panel_center.add(cb4);
       
        panel_south.setLayout(fl);
        panel_south.add(bt_ok);
        panel_south.add(bt_cancle);
       
        this.setLayout(bl);
        this.add(lb_description, BorderLayout.NORTH);
        this.add(panel_center, BorderLayout.CENTER);
        this.add(panel_south, BorderLayout.SOUTH);
       
    }
}

public class CheckboxEx {

    public static void main(String[] args) {
       
        CheckboxEx_Sub ex = new CheckboxEx_Sub();

    }
}